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The purpose of this tutorial paper is to present a broad overview of photon-pair generation through the spontaneous four wave mixing (SFWM) process in optical fibers. Progress in optical fiber technology means that today we have at our disposal a wide variety of types of fiber, which, together with the fact that SFWM uses two pump fields, implies a truly remarkable versatility in the resulting possible photon-pair properties. We discuss how the interplay of frequency, transverse mode, and polarization degrees of freedom—the first linked to the latter two through fiber dispersion—leads to interesting entanglement properties both in individual degrees of freedom and also permitting hybrid and hyper entanglement in combinations of degrees of freedom. This tutorial covers methods for photon-pair factorability, frequency tunability, and SFWM bandwidth control, the effect of frequency non-degenerate and counterpropagating pumps, as well as methods for characterizing photon pairs generated in optical fibers.
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This content will become publicly available on May 28, 2026
Progress toward photon-pair efficiency optimization using four-wave mixing in few-mode fibers
Intermodal four-wave mixing (FWM) process in few-mode fibers (FMFs) could be utilized for entangled photon-pair generation. Previous studies mainly performed in single-mode fibers suffered from the significant Raman scattering background from the glass fiber. Therefore, the instantaneous Raman and FWM effects would compete; this could be avoided in FMFs if the modal dispersion is larger than the Raman gain spectra. Utilizing two pumps in different modes in FMFs will generate photon pairs in various modes. Here, we study the effect of pump spectral separation on the intermodal FWM power and bandwidth using a seeding technique. It is concluded that the further the pumps and intermodal FWM idler and signal are from each other spectrally, the smaller the photon efficiency and larger the bandwidth. Experimental results for two FMFs of different differential mode group delay values are presented.
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- Award ID(s):
- 2301870
- PAR ID:
- 10594395
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Applied Optics
- Volume:
- 64
- Issue:
- 16
- ISSN:
- 1559-128X; APOPAI
- Format(s):
- Medium: X Size: Article No. 4654
- Size(s):
- Article No. 4654
- Sponsoring Org:
- National Science Foundation
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